17th December 2022
There has been extensive snow transport today in the Northern Cairngorms. The strong South-Westerly winds have started to redistribute snow from the southerly aspects to mainly the North and North-East aspects.
The most significant windslab accumulations are in wind sheltered locations above 900 metres. However, there is also drifting noticeable at lower elevations down to around 600 metres.
Overnight and tomorrow the winds will change again, becoming Southerly and then backing to the South-South-East by dawn. This will create further accumulations on North-West, North and North-East aspects. Given the gale force winds cross loading will also occur onto West and East aspects, and there may be accumulations at low elevations. There is a huge reservoir of relatively soft snow to be transported from the high plateaus of Beinn a’Bhuird in the Southern Cairngorms forecasting area.
Today was not without interest. I remote triggered a windslab avalanche from 50-100 metres away, which was around size 2. I came off skis and sunk into new windslab to just above the knee. Immediately, I triggered a weak layer under my feet with an audible whoopmf.
I was on a small convex roll of 26 degrees, but the failure propagated across the slope into steeper terrain with greater snow depth. The crown wall was greater than 1 metre in height and located close to the coire rim (see pictures below). This avalanche was significant as it went to the ground. There was also evidence of an avalanche over night in Coire Cas.
You do have to take evidence of instability when you can get it, the avalanche hazard is Considerable.
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